JPS58168488A - Automatic laser welding device of supporting grid for nuclear fuel assembly - Google Patents

Abstract

PURPOSE:To weld the many welding points of a supporting grid for a nuclear fuel assembly automatically by a laser with high accuracy, by combining an image processing unit with an aiming optical system for welding laser and a numerical controller. CONSTITUTION:A welding laser 3 is placed so as to face the supporting grid 1 on a supporting base 2. A TV camera 4 is mounted in the position where the eyepiece lens of the aiming optical system of the laser 3 is mounted, and the image of the position to be irradiated with the laser beam is picked up with the optical system. After the positioning of the beam and the welding point, a signal is fed from a numrical controller 5 to the controller 31 of the laser 3, and the laser beam controlled of the quantity of heat input is irradiated to the welding point. The signal of the image information with the camera 4 is display on a monitor 6, and the deviation in the positions between the point to be irradiated with the beam and the welding point is determined with an image processing device 7 and is inputted to the unit 5, by which the positioning is adjusted finely. A signal is then fed to the unit 31 and the laser 3 is emitted, whereby the welding point is welded.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to an automatic radar device for a support grid for a Yamei #i nuclear fuel assembly.

It is well known that support grids are used in nuclear fuel assemblies to bundle a large number of fuel rods and maintain proper spacing from one another. This support lattice consists of a strip 1 made of a nickel-based alloy [all assembled in a lattice shape, with many welding points ITIcJ!, such as the intersections of the vertical and horizontal strips and the intersection with the outer circumferential strip. are assembled next to each other.

This TIG welding involves manual welding of thin-walled strips, and therefore requires a high level of skill in assembling the support grid, and there is also the possibility of failure due to manual welding, in which case there is no way to correct it. There was a drawback that it cost a lot of time.

The main purpose of this invention is to automate the welding work of support grids with a large number of 11m points, and basically it is a precision positioning method by applying IIU image processing technology to laser welding by NC control. The aim is to provide an automatic laser welding device that can achieve a fully automatic and uniform welding finish by combining the following.

That is, the automatic laser welding device for support grids for nuclear fuel assemblies of the present invention is equipped with an aiming optical system that captures the laser beam irradiation position within the field of view, and uses an fI-m laser and an l! ! a support stand that moves with said support grid to align said irradiation position with respect to a large number of welding points of a support grid for a nuclear fuel assembly to be in contact; an image processing device that generates an output corresponding to a positional deviation between the supporting grid bath contact position within the field of view and the irradiation position from the gI signal of the red imaging device and determines whether the positional deviation is present or not;
The support table is roughly aligned based on the position information program of each welding point input in advance, and the support table is adjusted so that the position deviation is eliminated by the output of the m11'#1 processing device. It is characterized by being equipped with a numerical control device (N'C device) that performs a fine positioning operation and then fires a laser beam to perform welding.

The automatic laser welding device of the present invention has such m-deficiency!
ntf, many # of thin-walled support grids! rI! Even if the NC device alone cannot perform accurate positioning due to the pitch deviation between each welding point, since the image processing device is combined with the welding laser aiming optical system and the NC device, The positioning of numerous welding points one after another is automatically achieved with a high degree of bulk, and uniform welding is achieved at each bath contact point by laser welding without manual work! It is possible to create a department.

To describe this invention in detail with reference to the drawings, FIG. 1 is a block diagram showing the basic configuration of the device of the invention, and FIG.
In the explanatory diagram showing the kl image, pl (1) is the support grid to be welded 1, and (2) is the support grid (1) in the horizontal direction in the X and Y directions (indicated by arrows) perpendicular to each other. This is a movably supported support stand with a positioning function, and the s-device laser (3
) are placed. This welding laser (3) fully controls the start and stop of the laser beam by external input.
ll device 181), a laser generator whose start/stop is controlled by the control device 181), and a laser beam from the laser generator f# which is guided to the welding point of the supporting grid (II) to be in contact with it. The main system consists of a beam splitter and a condenser mirror, an illumination light source, and a condenser lens.
), a beam splitter (b), an objective lens ring, and a filter (2), so such a welding laser (3) itself is well known. In this invention, a television camera (4) is attached to the position where the eyepiece of the aiming optical system of the welding laser (3) is attached, and the television camera (4) uses the sighting optical system to detect images within its field of view. The position of the reference mark, that is, the laser beam irradiation position, is determined along with its 8 surroundings. Further, the support base (2) aligns the numerous bath contacts of the support grid (1) with respect to the laser beam irradiation position as described above, but in this invention, the numerical control device (5) is used for this alignment. ) is provided, and after the alignment is completed, the welding laser (3) is transmitted from this numerical control device (5).
) to irradiate the welding point with a laser beam adjusted to provide a pre-added amount of heat input to the bath by sending a signal to the control device (-) of ().

The imaging signal from the above-mentioned television camera (4) contains ij1g1 information in the vicinity of the support grid welding point centered on the laser beam irradiation position of the welding laser (3), and is displayed on the coflf monitor (6). Scratch 4i showing the positional deviation between the laser beam irradiation position (center point) and the bath contact!
An image processing device (7) is provided to obtain i.

This positional deviation signal is input to the numerical control device (5) and is used for fine adjustment of positioning as described below.

That is, in this invention, the welding target is a support grid, which is geometrically simple, and the position coordinates of the many welding points on the support base (2) are relatively regular. The positional coordinates of each welding point of the support grid (1) set on the support stand are calculated based on the laser beam beam position at which is determined by the arrangement relationship between the bath contact laser (3) and the support stand (2). Program the control device (51),
A support stand (2) is created for each contact point according to the contents of this program.
is controlled to achieve rough positioning. Once this rough positioning has been completed, the monitor (6)
As shown in the figure, the welding point Q of the intersection of the strips roughly aligned using the program of the support grid (1) shown in the figure is shown in one direction, and the reference position side is also displayed at the same time in this screen. ing. Let the XY position values of the bath contact point (lit be (x, y), and the coordinate values t(xo, yo) of the reference position times, ii
*The processing device (7) has position deviation signals (ΔX, ΔY) corresponding to
A stop signal is given to the numerical control device (5) at a position where the temperature becomes substantially zero. In this way, the numerical control device (5)
Then, after the rough positioning is completed, the support base (2) is controlled to perform a fine positioning operation, and then the fine positioning operation is completed (by a stop signal from the image processing device (7)). Therefore, after this operation is completed, the lit of the monitor (6) is improved to l! The position of the contact point aυ overlaps with the reference position side, and in this way, when the position deviation signal becomes substantially zero, a signal is sent from the numerical control (5) to the control device 181) of the welding laser (3). is supplied to emit a laser beam. This laser beam is precisely irradiated onto the targeted welding point as described above and has an intensity and duration that provides a preset f# tangent heat input, thus terminating the irradiation at 111 By transmitting the information from device a1 to the numerical control device (5), the numerical control device (5) starts the rough position alignment operation for the next welding point, and then automatically adjusts the operation for many welding points in the same way. S contact is performed together with program control.

As described above, according to the present invention, slight irregularities in the bath caused by differences in welding technique with TlG11 welding in conventional work can be prevented in advance. The automated operation of laser welding, which allows you to set the welding conditions, produces almost no welding and produces a uniform welding finish with no irregularities, making it possible to assemble support grids with no defects without the need of skilled workers. In addition, the accuracy of the positional information of each welding point for rough positioning, which is initially programmed into the numerical control device, is so rough that it is within 1klililiil of the image taken by a television camera processed by the image processing device. Therefore, there is an advantage that the device can be easily handled.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the basics *g of this invention, and FIG. 2 is an explanatory diagram showing an example of a monitor IIi image. (1): Support grid, (2): Support stand, (3): Welding laser, (4): Television camera, (5) = lll value control device, (6): Monitor, (71' iki iron Processing device, α theory: IW contact, ■Two reference positions. Agent: Attorney Sanro Kimura

Claims (1)

[Claims] A welding laser equipped with an aiming optical system that captures the laser beam irradiation position within its field of view, and moving the support grid to align with the irradiation position with respect to a large number of 811 points on the support grid for the nuclear fuel assembly to be welded. and an imaging device that images the field of view of the aiming optical system.
an its processing device that generates an output corresponding to the positional deviation between the support grid welding point position within the field of view and the irradiation position from the I signal and determines the presence or absence of a positional deviation; Based on the position information program, the tube is coarsely positioned on the support base, and the output of the image processing device is used to perform fine position alignment on the support base so that the position deviation is eliminated, and then a laser beam is emitted.
! 1. A laser automatic control WC device for a support grid for a nuclear fuel assembly, characterized in that it is equipped with a numerical control device that performs contact.